<?php
/*
 * Copyright (c) 2013 Eugene Kuzmenko
 *
 * Permission  is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in  the Software without restriction, including without limitation the rights
 * to  use,  copy,  modify,  merge, publish, distribute, sublicense, and/or sell
 * copies  of  the  Software,  and  to  permit  persons  to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The  above  copyright  notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE  SOFTWARE  IS  PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED,  INCLUDING  BUT  NOT  LIMITED  TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS  FOR  A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS  OR  COPYRIGHT  HOLDERS  BE  LIABLE  FOR  ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 * 
 * For more information, see <http://www.aljey.com>.
 */

namespace Al\Core\Lib\CacheDriver;

use Al\Core\Lib\AbstractProxiedParameterHolder;

/**
 * Provides persistent storage in the php apc cache through a highly convenient
 * array-like interface.
 * 
 * You have to install a php apc extension to use this cache driver:
 * <code>
 * sudo apt-get install php-apc
 * </code>
 *
 * @author Eugene Kuzmenko <mail@aljey.com>
 */
class APC extends AbstractProxiedParameterHolder {
  
  /**
   * {@inheritDoc}
   */
  public function __construct() {
    $info = apc_cache_info('user');
    if (!isset($info['cache_list'])) {
      $info = apc_cache_info();
      foreach ($info['cache_list'] as &$val) {
        if (!isset($val['info'])) {
          $val['info'] = $val['key'];
        }
      }
      unset($val);
    }
    parent::__construct(array_map(function ($val) {
      return $val['info'];
    }, $info['cache_list']));
  }
  
  /**
   * {@inheritDoc}
   */
  public function delete($offset) {
    apc_delete($offset);
  }
  
  /**
   * {@inheritDoc}
   */
  public function get($offset) {
    return apc_fetch($offset);
  }
  
  /**
   * {@inheritDoc}
   */
  public function set($offset, $value) {
    if (isset($this[$offset])) {
      apc_store($offset, $value);
    } else {
      // minimizes the risk of race conditions in multi-process servers
      apc_add($offset, $value);
    }
  }
  
}